One purpose of this research is to examine the influence of aging upon the development and enactment of automatic and effortful attentional processes. We found previously that old adults are unable to attain automatic detection after extensive practice. We are examining the extent to which old adults can go beyond the first level of learning, i.e., "associative" learning, to priority learning which results in automatic detection, a direct and immediate response of the attentional system to the item to be detected. A second purpose of this work is to investigate the relation between age and distractibility. An experimental procedure was developed where subjects are asked to repeat messages presented to one ear (shadowing) while ignoring simultaneous messages in the other ear. Low distractibility is demonstrated by equivalent shadowing performance with and without simultaneous (and different) messages in the other ear. It was previously reported that age and distractibility are directly related. The increase in distractibility with increased age was especially prominent in old adults who had been hospitalized within the prior two years and were on prescription medication. A more precise investigation is now being completed into the moderating effect of health. Also being completed is an investigation in the specific source of the apparent age-related increase in distractibility and reduced ability to control attention. A third goal of this work is to determine the parameters of thought production as well as related mental activity such as insight, attention and sustained attention as phenomena, their interrelations, and the susceptibility to the influence of aging in adulthood. A fourth goal is to examine the relation between memory or forgetting and aging. Six-year longitudinal changes in immediate and short-term delayed memory have been demonstrated. Also demonstrated is the age dependence of forgetting rate during a 24 hour period.